Conditions: Baltimore, Maryland, 02/05/2023 12:40:03 pm
Temperature

47°

Mostly Cloudy

19°

Dew Point
Relative Humidity

32%

Feels Like

43°

Wind (SSW)

9mph

Air Pressure

30.17

Sun
Sun Rise

07:09 AM

Sun Set

05:31 PM

Day Length

10:22 Hours

Difference

2 min 10 sec gain

Moon
Moon Rise

05:27 PM

Moon Set

07:30 AM

Next: Full Moon

Feb 05,2023

Moon Phase

Waxing Gibbous

Climate
Average Low

25°

43°

Average High
Record Low

-1°


(1996)

73°


(1991)
Record High
Conditions

Wednesday Morning Winter Mix: Two American Models Still Split On Timing And Impact

snow forecast
Maryland Weather
Winter Weather
Forecast
Warnings

January 24, 2023

Tuesday Mid-Day Update

The marginal winter event for our region on Wednesday would be minor in a normal winter. This is a rare winter, however, so it is worth the attention since we are out of practice on how to handle this.  The added concern is the timing, as I have been saying for a few days.  Now we can see the contrast between the two American Computer Models. I will break them down below but add the caution that more data is arriving now. I also want to share what I will be focusing on with my work.

Concern Time: 7 AM to 11 AM Wednesday

Getting the arrival time may impact the commute conditions and some schools.  One or two hours off can make or break this forecast and inclement weather policy calls. It is possible this arrives at the tail end or after school busses, then changes to rain before the afternoon ride.  That is part of the challenge.

Comparing Models

The GFS Model (still under scrutiny) is faster, thus tapping in and holding cold air longer.

The NAM Model is the higher resolution but has an error of being 1 to 2 hours slow, which is later. This allows ‘warm enough air’ to expand north and limit any winter impact on our region.

Note: Due to the model error, I am purposely comparing off hours. The GFS 7 AM to the NAM 8 AM; The GFS 10 AM to the NAM 11 AM.

Early Morning

The GFS Model is much faster, allowing the leading band to be snow. This would be associated with an upper-level warm front. I’ve seen this followed by a lull, then the main shield of precipitation arriving later.

The NAM Model is delayed with the leading edge of snow near and west of Cumberland.

January 24 weather snow rain models morning

 

Late Morning

The GFS has a solid coverage of snow including metro Baltimore (please note the temps above freezing below).

The NAM Model is simply much slower, barely reaching Northern Carroll County in Maryland and York County in PA. Metro Baltimore not yet (per this model).

January 24 weather snow rain models morning late

 

Closer Look At Each Model Below

Weather Alerts from NWS

UPDATED MAP!

I still think Frederick to Westminster may get added or have worthwhile impact for a bit. Stay close for updates.

New Winter Weather Alerts Wednesday January 25

My Suggested Impact

This map is the same as I posted last night. I am keeping this up for consistency. I will post a snow map in my evening report.

January 23 weather snow impact chances

 

AFTERNOON UPDATE

I posted this on social media…

Afternoon Model Analysis Comparing latest plots:
1 PM (18Z) to Doppler Radar centered in Little Rock, AR.
GFS Model = closest to verifying!
Euro SLOW (older run/having mainframe issues).
Canadian GEM is ALSO TOO SLOW.
*Why is this important?
GFS Model has been the fastest to bring snow to MD on Wed AM and hold cold.
*TIMING IS KEY and a few hours earlier will make or break the impact for our region. I am trying to be overly cautious, but this does fit the models bias running too slow.
This was my recent update. I will have more later.

Storm nowcasting 1 Pm Tuesday Snow Arkansas

 

TUESDAY NIGHT UPDATE

Click here for the Full Report

January 25 Snow Profile Maryland

 

Animation

The Warmer Solution: For Argument’s Sake

I don’t want you to think I am biased towards the cold model… So let’s use the warmer NAM as the baseline.  Compare to the GFS Model Snapshots below.

NAM 6 AM to Midnight

The later arrival allows more warm air, and mostly heavy rain in the afternoon and evening.

January 24 weather snow radar NAM

 

 

Snapshots

8 AM

January 24 weather radar forecast snow NAM 8 AM

 

11 AM

Suggested first flakes for the Northwest hills seems late.

January 24 weather radar forecast snow NAM 11 AM

 

12 PM

This noon plot seems a little too late for the onset in metro areas.

January 24 weather radar forecast snow NAM 12 PM

 

2 PM

I do agree with the expansion of moderate to heavy rain.

January 24 weather radar forecast snow NAM 2 PM

 

GFS Model Snapshots

This may be too aggressive with the cold air.

7 AM

This suggests a leading band of snow by sunrise into Northeast Maryland based on a mid-level warm front at cloud level.  Then a lull for a few hours between the main shield of snow/rain.

January 24 weather radar forecast snow GFS 7 AM

 

10 AM

This is very aggressive with the bulk of snow. With this arriving earlier, it allows the marginal cold air to be tapped and held a few extra hours.

January 24 weather radar forecast snow GFS 10 AM

 

1 PM

This does hold the snow in northern Maryland, but compare to the temperatures below, if this verifies it would be slushy with wet roads.

January 24 weather radar forecast snow GFS 1 PM

 

Temperatures

These are based on the GFS Model, so when comparing the snow maps… look for the 32ºF line for the best chance for stickage and accumulation.  That matches up with my suggested impact map above.

7 AM

January 24 weather radar forecast temperatures GFS 7 AM

 

10 AM

January 24 weather radar forecast temperatures GFS 10 AM

 

1 PM

January 24 weather radar forecast temperatures GFS 1 PM

 

4 PM

January 24 weather radar forecast temperatures GFS 4 PM

My Take Away:

TIMING!  I will be watching for the Canadian and European Model package to fully display.  I am looking more for any consistency or trends on speed.

This afternoon I will be doing a nowcasting analysis. Over a few hours I will be comparing each model to the variation of both radar and ground observations for the leading edge of precipitation.

I am inclined to find a middle ground between these two outputs. The GFS might be too aggressive, while the NAM is a little too slow and warm.

I also would lean more pessimistically against higher snow totals, due to the ground temps AND timing extending to midday.

We will turn to all rain in the afternoon.

The National Weather Service is likely to post some advisories for Maryland, Northern Virginia, and West Virginia. I will pass along what I see when that data arrives.

 

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Also See:

Winter History: Low Snow And Late Starts

See my research based on Baltimore data since 1883.

 

 

 

STEM Assemblies/In School Fields Trips Are Back

Click to see more and ‘Book’ a visit to your school

 

My Winter Outlook: Not A Typical La Niña!

I see many factors to support colder influence with multiple systems. Early and later in winter. Check it out.

Winter Outlook 2023 For Snow Not Typical La Niña Plus Polar Vortex Disruption

 

 

Also See The Winter Outlook Series:

Atmospheric Memory Suggests Active Winter Storm Pattern Outlook

 

Winter Outlook 2023 From NOAA Very Different Than Farmers Almanacs

Farmer’s Almanac Comparison

Winter Outlook 2023 Early Look At Snow From Two Farmers Almanacs

Triple Dip La Niña Winter

Winter Outlook 2023 La Niña Triple Dip Expectations

 

CONNECTION TO WINTER?

If you want a snowy winter, this is what you might want to look for in the rest of the tropical season. (You might be seeing a lot of commercial snow removal people out this Winter).

Record August For No Named Tropical Storms: Closer Look At Snow Following

 

Wooly Bear Caterpillars

Winter Weather Outlook From The Wooly Bear Caterpillar

 

Persimmon Seeds

Winter Weather Outlook: Persimmon Seeds And Snow Folklore

 

Click to see Top 20 and MORE

Winter Weather Folklore Top 20 And More Outlook Signals From Nature For Cold And Snow

 

 

 

 

Normals And Records: Maryland and Baltimore Climate History

 

Please share your thoughts, best weather pics/videos, or just keep in touch via social media